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1.
Nat Commun ; 12(1): 334, 2021 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-33436570

RESUMEN

Magnetized plasma interactions are ubiquitous in astrophysical and laboratory plasmas. Various physical effects have been shown to be important within colliding plasma flows influenced by opposing magnetic fields, however, experimental verification of the mechanisms within the interaction region has remained elusive. Here we discuss a laser-plasma experiment whereby experimental results verify that Biermann battery generated magnetic fields are advected by Nernst flows and anisotropic pressure effects dominate these flows in a reconnection region. These fields are mapped using time-resolved proton probing in multiple directions. Various experimental, modelling and analytical techniques demonstrate the importance of anisotropic pressure in semi-collisional, high-ß plasmas, causing a reduction in the magnitude of the reconnecting fields when compared to resistive processes. Anisotropic pressure dynamics are crucial in collisionless plasmas, but are often neglected in collisional plasmas. We show pressure anisotropy to be essential in maintaining the interaction layer, redistributing magnetic fields even for semi-collisional, high energy density physics (HEDP) regimes.

5.
Am J Cardiol ; 82(5): 574-9, 1998 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-9732882

RESUMEN

We have taken a stepwise approach to improving the dosing of continuous intravenous heparin in patients with acute coronary syndromes. Our primary objective was to use computer modeling to develop a nomogram for managing heparin therapy and to put in place a continuous quality monitoring system to evaluate the nomogram's effectiveness. We prospectively collected data on 41 patients with unstable angina or myocardial infarction who were treated with heparin. Their response to heparin was computer modeled and the dose to achieve an activated partial thromboplastin time (aPTT) ratio of 2.0 was established. This dose was regressed against all demographic characteristics to establish predictors of heparin dose (phase I). The regression formula was used prospectively in 110 patients to initiate the infusion rate of heparin and a bolus dose to achieve an aPTT ratio of 2.5. Subsequent dosage adjustments were achieved by computer modeling the patient's aPTT response (phase II). A nomogram was developed that simulated the decisions achieved using computer-assisted methods. This was retrospectively tested and then prospectively tested in 50 patients using nursing staff (phase IV). The nomogram was then made generally available (phase IV) and has been tested in an additional 310 patients. Phase I: Of the original 41 patients, 32% of the aPTT ratios were in the therapeutic range, 36% were supratherapeutic, and 32% were subtherapeutic after the first 24 hours. Phases II and III resulted in 85% of the aPTT ratios between 1.5 and 2.5 at 24 hours. Phase 4 had similar results in 310 patients. The use of computer-assisted or a computer-generated nomogram to adjust heparin therapy results in better control of heparin therapy than using standard methods.


Asunto(s)
Angina Inestable/tratamiento farmacológico , Anticoagulantes/administración & dosificación , Simulación por Computador , Heparina/administración & dosificación , Infarto del Miocardio/tratamiento farmacológico , Garantía de la Calidad de Atención de Salud , Adulto , Anciano , Anticoagulantes/efectos adversos , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Femenino , Heparina/efectos adversos , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Tiempo de Tromboplastina Parcial , Grupo de Atención al Paciente , Estudios Prospectivos , Estudios Retrospectivos , Terapia Asistida por Computador , Resultado del Tratamiento
6.
Arch Dermatol ; 133(9): 1143-5, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9301592

RESUMEN

BACKGROUND: Patients with auriculotemporal nerve syndrome (Frey syndrome) have facial flushing, sweating, or both localized to the distribution of the auriculotemporal nerve that occurs in response to gustatory stimuli. In adults, the syndrome usually results from surgical injury or trauma to the parotid gland. The condition is rare in infants, but usually manifests during infancy with the introduction of solid food, thus leading to the misdiagnosis of food allergy by physicians unfamiliar with the syndrome. OBSERVATIONS: We describe 8 children with auriculotemporal nerve syndrome who manifested with flushing only. The reaction was erroneously attributed to food allergy in most cases. Six of the 8 patients were delivered with forceps assistance. The remaining 2 patients, with disease onset during the first 3 months of life, had bilateral involvement without known trauma. CONCLUSIONS: Auriculotemporal nerve syndrome may manifest during infancy as flushing with eating food. In contrast to the syndrome in adults, gustatory sweating is rarely associated. The known use of forceps to assist in the delivery of at least 14 of the 28 previously reported pediatric cases and in 6 of our 8 patients suggests that trauma to the parotid region may be responsible for the condition in most infants, as it is in adults. Auriculotemporal nerve syndrome in infancy should be recognized as a benign condition that often resolves spontaneously. Treatment is ineffective and unnecessary.


Asunto(s)
Rubor/diagnóstico , Sudoración Gustativa/diagnóstico , Traumatismos del Nacimiento/complicaciones , Femenino , Rubor/etiología , Humanos , Lactante , Masculino , Sudoración Gustativa/etiología
7.
Am Fam Physician ; 56(2): 443-50, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9262525

RESUMEN

Benign dermatoses in newborns must be distinguished from more serious disorders with cutaneous manifestations. Erythema toxicum neonatorum, transient neonatal pustular melanosis, sucking blister, miliaria and mongolian spots are among the many benign skin conditions that can occur in newborns. Recognition of these dermatoses allows the physician to proceed appropriately, reassure the parents and initiate further evaluation or treatment as necessary. To avoid adverse sequelae, special attention must be given to more persistent conditions and those with the potential for complications or malignant transformation. Consultation with a pediatric dermatologist, a plastic surgeon or a neurosurgeon may be necessary.


Asunto(s)
Enfermedades de la Piel , Diagnóstico Diferencial , Humanos , Recién Nacido , Enfermedades de la Piel/diagnóstico , Enfermedades de la Piel/terapia
9.
J Cutan Pathol ; 23(4): 323-7, 1996 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8864919

RESUMEN

Cutaneous lesions of anaplastic large cell (CD30+) lymphoma (ALCL) typically present as solitary or multiple ulcerated nodules. This tumor is histologically characterized by a diffuse dermal and sometimes subcutaneous infiltrate composed of bizarre, pleomorphic, neoplastic cells that may be occasionally multinucleated. We report a case of extranodal spread of ALCL to the skin in a 2 1/2-year-old boy presenting as a widespread papular eruption that on biopsy showed lymphoma restricted to the perivascular and periadnexal dermis.


Asunto(s)
Vasos Sanguíneos/patología , Ganglios Linfáticos/patología , Metástasis Linfática/patología , Linfoma Anaplásico de Células Grandes/patología , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/secundario , Preescolar , Humanos , Linfoma Anaplásico de Células Grandes/diagnóstico , Masculino , Neoplasias Cutáneas/diagnóstico
11.
Semin Dermatol ; 13(4): 256-61, 1994 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-7848819

RESUMEN

With the current resurgence of sexually transmitted diseases (STDs), familiarity with the clinical manifestations of STDs in neonates and infants is essential to minimize the tragic consequences. The recognized routes of transmission of the diseases include transplacental, intrapartum, and postpartum exposure. This discussion will be confined to infections caused by syphilis, herpes simplex virus, human papillomavirus, gonorrhea, and chlamydia emphasizing clinical aspects in this population.


Asunto(s)
Enfermedades Bacterianas de Transmisión Sexual/congénito , Enfermedades Virales de Transmisión Sexual/congénito , Preescolar , Infecciones por Chlamydia/congénito , Infecciones por Chlamydia/transmisión , Gonorrea/congénito , Gonorrea/transmisión , Herpes Simple/congénito , Herpes Simple/transmisión , Humanos , Lactante , Recién Nacido , Papillomaviridae , Infecciones por Papillomavirus/congénito , Infecciones por Papillomavirus/transmisión , Sífilis Congénita/transmisión , Infecciones Tumorales por Virus/congénito , Infecciones Tumorales por Virus/transmisión
14.
J Am Acad Dermatol ; 25(2 Pt 2): 418-22, 1991 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-1894784

RESUMEN

This report describes a black woman with a history of cutaneous Mycobacterium kansasii responsive to antituberculous drugs. A culture several years later of cutaneous lesions was also positive for Histoplasma capsulatum. Both cutaneous diseases are rare and most often occur in immunocompromised hosts. There is no known association between these two diseases. This patient may have an as-yet unidentified immunodeficiency that predisposes her to these rare infections. Her case emphasizes the importance of repeat biopsy for atypical skin lesions.


Asunto(s)
Dermatomicosis/patología , Histoplasmosis/patología , Infecciones por Mycobacterium no Tuberculosas/patología , Enfermedades Cutáneas Infecciosas/patología , Femenino , Humanos , Inmunidad , Persona de Mediana Edad
15.
Arch Dermatol ; 127(5): 704-6, 1991 May.
Artículo en Inglés | MEDLINE | ID: mdl-2024989

RESUMEN

We report a case of acquired porphyrinemia in a liver transplant recipient. Thrombosis of the portal vein and hepatic artery led to massive necrosis of the patient's first donor liver, necessitating its removal. After an 18-hour anhepatic period, a second donor liver was transplanted. During this interval, the patient was warmed with an infrared heat lamp that emitted bright visible light. Following the anhepatic period, a photodistributed cutaneous erythema was noted. The level of total serum porphyrins during the anhepatic period was significantly elevated at 1.548 mumol/L (normal, less than 0.018 mumol/L). Fractionation showed that the levels of the hydrophobic porphyrins, coproporphyrin and protoporphyrin, were elevated, while the levels of the hydrophilic porphyrins remained normal. Following the successful second liver transplantation, the patient's porphyrin levels declined. This is the first reported case of acquired porphyrinemia in a liver transplant recipient.


Asunto(s)
Trasplante de Hígado , Porfirinas/sangre , Niño , Coproporfirinas/sangre , Arteria Hepática , Humanos , Rayos Infrarrojos , Hígado/patología , Trasplante de Hígado/efectos adversos , Masculino , Necrosis , Trastornos por Fotosensibilidad/etiología , Vena Porta , Protoporfirinas/sangre , Trombosis/etiología , Factores de Tiempo
17.
Int J Dermatol ; 29(5): 375-6, 1990 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-2361798

RESUMEN

A 58-year-old black man with leg ulcers of 43 years duration responded to pentoxifylline 400 mg tid in 8 months. The ability of pentoxifylline to increase erythrocyte flexibility and decrease blood viscosity was the basis for our use of this agent. Oral pentoxifylline may be a useful adjunct in healing sickle cell leg ulcers and preventing their recurrence.


Asunto(s)
Anemia de Células Falciformes/tratamiento farmacológico , Úlcera de la Pierna/tratamiento farmacológico , Pentoxifilina/uso terapéutico , Teobromina/análogos & derivados , Cicatrización de Heridas/efectos de los fármacos , Anemia de Células Falciformes/complicaciones , Enfermedad Crónica , Humanos , Úlcera de la Pierna/etiología , Masculino , Persona de Mediana Edad , Pentoxifilina/administración & dosificación , Pentoxifilina/farmacocinética , Recurrencia
18.
Gynecol Oncol ; 36(3): 338-42, 1990 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-2318442

RESUMEN

Sixteen patients with advanced epithelial ovarian cancer who were treated with cytoreductive surgery followed by multiagent chemotherapy were found to have residual tumor masses less than 2 cm in greatest diameter at reexploration and were treated with whole-abdominal radiation (19-31 Gy). Thirteen patients also received pelvic boosts to a total pelvic dose of 41-53.7 Gy. Radiotherapy was completed in all but 2 patients after treatment delays in 7 patients. Early treatment complications included myelosuppression in 11 patients, diarrhea in 3, and a self-limited small bowel obstruction in one. Delayed complications were severe and included 9 patients with radiation enterocolitis, 8 of whom required intestinal resection or diversion. One additional patient with radiation cystitis required instillation of formalin to control bleeding. Two patients are without evidence of disease 28 and 30 months following radiotherapy, while the remaining 14 patients have recurred after a median progression-free interval of 9 months (range 1-30 months). All patients who recurred failed within the treatment field and died of cancer after a median interval of 19 months following radiotherapy and 9 months after documentation of progression. These data suggest that few patients with persistent ovarian cancer following surgery and chemotherapy will be salvaged with radiotherapy.


Asunto(s)
Neoplasias Ováricas/radioterapia , Abdomen , Adulto , Antineoplásicos/uso terapéutico , Terapia Combinada , Epitelio , Femenino , Humanos , Persona de Mediana Edad , Recurrencia Local de Neoplasia , Análisis de Supervivencia
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